1. Field
Example embodiments relate to composite transparent electrodes, production methods thereof, and electronic devices including the same.
2. Description of the Related Art
Electronic devices such as flat panel displays (e.g., a liquid crystal display and a light emitting diode display), touch screen panels, photovoltaic cells, and transparent transistors typically include transparent electrodes. Materials for the transparent electrode may be required to have high transmittance (e.g., of at least 80%) and low specific resistivity. The currently available materials for the transparent electrode typically include indium tin oxide (ITO), tin oxide (SnO2), zinc oxide (ZnO), and the like. The ITO is an n-type semiconductor wherein the presence of SnO2 may result in the generation of oxygen vacancies and electrons. Electrical and optical characteristics of the ITO may depend on defects in the crystalline structure of In2O3. The ITO tends to have poor flexibility, and limited reserves of indium may inevitably result in an increasing cost thereof so that it may be advantageous to develop a material that as a substitute to ITO. Tin oxides (e.g., SnO2) are less expensive and chemically stable but may not be etched easily, their resistivity is higher than the resistivity of indium oxide and zinc oxide, and they may require a high process temperature. Zinc oxide is reported to have transmittance and electrical conductivity that are comparable to the transmittance and the electrical conductivity of ITO, but it is chemically unstable and may not provide a high etching ratio and a well-defined pattern when it is subjected to a wet etching process. In particular, electronic devices such as an organic light-emitting diode (OLED) may require a transparent electrode being prepared by vapor deposition at room temperature. However, most transparent electrodes including the aforementioned materials when deposited at room temperature tend to be amorphous or to have lower crystallinity, which may lead to lower conductivity and higher sheet resistance.
Therefore, it is desirable to develop an electrode material that may show high transmittance and enhanced conductivity even when formed by deposition at room temperature.